Portable and mobile radiotelephones, once a rarity, have now become almost commonplace. Many users now find a radiotelephone to be a personal and/or business necessity.
However, the use of a radiotelephone when driving can provide a safety hazard because the user must typically look away from the road, toward the control keypad, in order to dial the desired telephone number. This brief inattention to the driving environment can cause an accident, especially in fast-moving and/or congested traffic. Of course, it is possible to provide speed dial functions so that the user may preprogram commonly called telephone numbers into a memory in the radiotelephone and, when the user desires to place a call, the user simply punches in a smaller set of numbers, typically two or three digits, to cause the radiotelephone to extract the telephone number from the memory and dial the desired telephone number. However, the user is still required to temporarily divert his attention to the control keypad instead of to the driving environment. The diversion time is smaller, because of the reduced number of digits, but can still become significant in many traffic situations. In addition, the user must be able to remember the speed dial bin corresponding to the desired telephone number, must scroll through the speed dial bin numbers displayed on the control display (on systems which provide this feature), or must have a table which indicates the speed dial bin number for a desired telephone number or desired party. However, the latter two conditions still require the user to divert attention from driving conditions and look at the control display or the table. Also, the user must take the time to program the radiotelephone.
Furthermore, depending upon the design of the radiotelephone and the user's manual dexterity, one or both hands may be needed to initiate a call. This can reduce the user's ability to control the car or quickly respond to a changing traffic condition.
Many businessmen/businesswomen have a secretary. The need for the user to divert his/her attention from driving conditions in order to dial a telephone number would be eliminated if the user's secretary could, from a remote location, cause the radiotelephone to dial the desired telephone number. Therefore, there is a need for a radiotelephone which can be remotely controlled so as to cause the radiotelephone to dial desired telephone numbers with little or no action on the part of the user.
Typically, the radiotelephone is programmed by a dealer to allow the use of specified features and use in predefined areas. However, many users travel through one or more radiotelephone service areas in the course of their personal/business affairs and may find that additional areas, a different class of service, different operating privileges, etc., are desired. The process of changing any of these operating parameters is generally an inconvenience to the user because the user must return to the dealer to have the radiotelephone reprogrammed. It would be more convenient for the user if the radiotelephone could be remotely programmed by the dealer. Therefore, there is a need for a radiotelephone which can be remotely programmed by a dealer so as to change the class of service, areas of service, and other operating parameters. However, the radiotelephone should prevent unauthorized persons from changing the operating parameters.
Furthermore, in the case of a non-paying user or a stolen radiotelephone, it is desirable to prevent the further use of the radiotelephone. Therefore, there is a need for a radiotelephone which can be disabled by remote control. However, the radiotelephone should prevent unauthorized persons from disabling the radiotelephone.
Many radiotelephone users travel to different cities. This can make the user difficult to locate unless the user has provided his/her secretary with a table listing the system access telephone numbers for the different cities. Furthermore, if the user is trying to call a party, who has a radiotelephone, in another city then the user must look through the book to determine the system access telephone number for that city. It would be advantageous if the radiotelephone would allow for the system access telephone number for commonly used cities to be programmed into the radiotelephone so that neither the user nor the secretary had to look through the listings book. Therefore, there is a need for a radiotelephone which will store the system access telephone numbers for a plurality of cities.
In addition, there is also a need for a device for remotely programming the radiotelephone. The device must provide for convenient entry of any required passwords, access codes, security codes, instructions, etc., and display responses and instructions from the radiotelephone.